WinCE 微秒和毫秒级延时函数

//WINCE 微秒级延时函数

void delay_us(int n){

LARGE_INTEGER litmp;
LONGLONG QPart1,QPart2;
double dfMinus, dfFreq, dfTim;
if(QueryPerformanceFrequency(&litmp)==FALSE)
   {
       MessageBox(NULL,TEXT("Error：QueryPerformanceFrequency"),TEXT("Error"),MB_OK);
       return;

   }
dfFreq = (double)litmp.QuadPart;
QueryPerformanceCounter(&litmp);
QPart1 = litmp.QuadPart;
do
 {
   QueryPerformanceCounter(&litmp);
   QPart2=litmp.QuadPart;
   dfMinus=(double)(QPart2-QPart1);
   dfTim=dfMinus/dfFreq;
 }while(dfTim <0.000001*n);

}
 

//毫秒级的延时函数

void   delay_ms(DWORD   tmp_time)  
{  
 DWORD   start;  
 DWORD   time_i=0;  
 start=GetTickCount();  
 while(time_i<=tmp_time)  
  {  
     time_i=GetTickCount()-start;  
  }  

}